Kate busman



Feb. 23, SUSMAN LISTENING APPARATUS Filed Dec. 27, 1929 S .5 man Patented Feb. 23, 1932 PATENT OFFICE KATE susmm, or vmmu, AUSTRIA LISTENING APPARATUS Application filed December 27, 1929, Serial No. 416,860, and in Austria July 28, 1929.

This invention relates to improvements in listening apparatus or stethoscopes rendering audible to the human ear the characteristic sounds of engines, gears, watches, clocks and a so forth, in order to detect from the anomalies in saidsounds or noises, the irregularities of running of the engine or device tested.

One mode of carrying out the present invention is illustrated by way of example in .10 longitudinal section in the accompanying drawing.

A solid steel-bar 1 is provided at its bottom end with a depression 2 and the rim of the latter is placed onto the part or place of 5 the machine to be tested by listening. The bar is held by means of a sleeve 1". The top art of the steel-bar, which for example may be curved, is attached at 3 to a readily oscillating diaphragm 4, for instance of steelsheet or another material adapted for use in connection with dia hragms. Brackets 5, preferably of a rigi material, connect the circumference ofthe said diaphragm with the centre 6 of a second diaphragm 7, the circumference of which is attached at 8 to the rim of a sound box 9. The neck 10 of the latter rests on the bar 1.

In some cases it may be necessary to extend the listening apparatus. In order to attain this object the bottom end of the bar 1 is provided with a screw-thread 11, which fits into the screw-thread 12 of a winged nut 13. The latter is provided with a screwthread 14, passing into the opposite direction and adapted to cooperate with a screwthreaded extension member 15.

If the recessed end 2 of the solid bar 1 or of the extension member 15 is placed onto the engine to'be tested by listening, the 1ongitudinal oscillations, producedin the bar by the place under examination, are at first transformed into transverse oscillations in the diaphragm 4. The oscillations of the latter are transmitted to the diaphragm 7 by means of the preferably rigid brackets 5. Thereby the oscillations of the diaphragm 7 react on the oscillations of the diaphragm 4,

. so that the human ear hears a reproduction of the sound or noise of the engine which is 59 amplified by resonance in the sound box 9.

I claim- 1. Device for testing, by listening to the sounds or noises of engines and devices of any kind, the running conditions of said engines or devices, comprising in combination a solid bar, a. depression in one end of the latter, a sound box at the other end of said bar, a sound amplifying diaphragm, a readily oscillating diaphragm attached to the top part of the solid bar, brackets connectin 60 the peripher Y of said latter diaphragm wit the centre 0 the diaphragm first mentioned, for transforming the longitudinal oscillations of said bar into transverse oscillations and amplifying the sounds reproduced in 85 said sound box.

2. Device for testing, by listening to the sounds or noises of engines and devices of any kind, the running conditions of said engenes or devices, comprising. in combination a.solid bar, means for securing an extension member to one end of said bar, a dc ression in the free end of said latter, a soun box at the other end of said bar, a sound amplifying diaphra m, a readily oscillating diaphragm attache to the top part of the solid bar brackets connecting the periphery of sai latter diaphragm with the centre of the diaphragm first mentioned, for transforming the longitudinal oscillations of said bar into transverse oscillations and amplifying the sounds reproduced in said sound box.

In testimony whereof I afiix my signature.

KATE SUSMAN. 

